Encyclopaedia of Gardening 187 



Insects. The principal insect pests of plants are referred to under 

 their own names in this work, or in connection with the crops which 

 they affect, and remedies given. 



Inula (in-ula, perhaps a corruption of Helenium. Ord. Com- 

 positae). I. glandulosa is a fine hardy herbaceous perennial, grow- 

 ing about 1 8 ins. high, and with large deep yellow flowers in summer. 

 It is well worthy of a place near the front of the border. It thrives 

 in most fertile soils, and likes clay if friable. Propagation is by 

 division in spring. I. Helenium, the Elecampane, is a taller plant. 

 Hookeri is a fine pale yellow species blooming in late summer (see 

 the Botanical Magazine, t. 6411). 



lonopsidium, Violet Cress (ionopsid-ium. Ord. Cruciferae). 

 I. acaule is a dainty little violet-flowered hardy annual only grow- 

 ing about 2 ins. high. It will grow in almost any soil, and is raised 

 from seed sown where it is to bloom in spring (syn. Cochlearia 

 acaulis). 



Ipomaea, Convolvulus (ipomae-a, from ips, bindweed, and 

 homoios, similar. Ord. Convolvulaceae) . This genus is closely 

 allied to that of Convolvulus, and some plants commonly called 

 Convolvuluses are really Ipomaeas. C. major, for instance, is 

 really I. purpurea. Of the plants usually grown under the name 

 Ipomaea may be mentioned Bona-nox, a white hothouse evergreen 

 climber, blooming in late summer (see the Botanical Magazine, 

 t. 752) ; hederacea (syn. Nil), a blue half-hardy perennial (Bot. Mag., 

 t. 1 88), and its varieties grandiflora and Huberi variegata; Hors- 

 falliae, a rose winter-flowering hothouse evergreen; Leari (syn. 

 Pharbitis Learii), a blue autumn-blooming hothouse evergreen 

 (Bot. Mag., t. 3928); and versicolor (syn. Mina lobata), a hardy 

 annual, various colours. The annuals are raised from seed, the 

 perennials from cuttings in sandy peat in heat. Loam, with some 

 leaf soil, decayed manure, and sand, makes a suitable compost. The 

 hothouse climbers should be thinned after flowering. 



Iresine (iresi-ne, from eiros, wool, in allusion to the woolly shoots. 

 Ord. Amarantaceae) . The Iresines were more important plants in 

 the old carpet-bedding days than they are now. They are tender 

 perennials, dwarf, with narrow, highly coloured leaves, which made 

 them useful for formal designs. They thrive in most soils. Propa- 

 gation is by cuttings in gentle heat towards the end of summer. 

 They should not be potted off till spring, and need very little water 

 in winter. Herbstii (see Botanical Magazine, t. 5499), Wallisii, and 

 Lindcni all have dark leaves. 



Iris (i-ris, from iris, the eye. Ord. Iridae). The Iris is a strik- 

 ingly beautiful hardy flower, and it is not surprising that many 

 people like to grow a collection. But the species need not all be 

 put together. The larger, such as the Flag, English, and Spanish, 

 may be planted in herbaceous borders; and the smaller on the 

 rockery. The Flags have rhizome roots and evergreen foliage;- the 

 English and Spanish have bulbous roots and lose their leaves every 



